In this Competitive Grant Revision to the Fast-Track SBIR: "A Compact X-ray Station for Protein Crystallography (CXS)," we describe proposed enhancements and upgrades to the Compact Light Source (CLS) that will result in a substantial increase in x-ray flux to the CXS. The CXS is a project to design and build a combination of x-ray optics, endstations, and software that use the monochromatic, tunable x-ray beam produced by the CLS. The CXS project, though not yet complete, has already resulted in an almost turnkey scientific instrument - a synchrotron-like x-ray system - for structural biologists at academic and corporate research centers. In order to make a significant reduction in data collection time, especially for small crystals, enhancements to the CLS are needed. In response to the NIH Notice: "NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications" - NOT-OD-09-058, we plan to expand the scope of the CXS grant to include several hardware upgrades to the CLS and to fund additional operations time. These efforts will result in significantly more x-ray flux and better reliability of the CLS, which together will greatly improve the impact and performance of the CXS. PUBLIC HEALTH RELEVANCE: The Compact X-ray Station for Protein Crystallography (CXS), along with the Compact Light Source (CLS), provides the technology to bring state-of-the-art macromolecular crystallography to structural biologists in their own local or regional laboratories. This tool will allow a wider community of researchers to conduct a broad range of structure determination experiments that will lead to better understanding of the role of proteins and other macromolecular assemblages involved in disease and therapy.